Several attempts have been made to modify the testosterone molecule by chemical means in order to render it orally effective, i.e. to delay metabolism in the liver. In this regard, the longest known testosterone derivative is 17a-methyltestosterone (Ruzicka et al. 1935) which is a fully effective oral androgen preparation. 17a-methyltestosterone is quickly absorbed and maximal blood levels are observed 90 to 120 minutes after ingestion. The half-life in blood amounts to approximately 150 minutes (Alkalay etal. 1973).

Ever since this steroid was introduced for clinical use, hepatotoxic side-effects such as an increase in serum liver enzymes (Carbone etal. 1959), cholestasis of the liver (de Lorimer etal. 1965; Werner etal. 1950), and peliosis of the liver (Westaby et al. 1977) have been reported repeatedly. It is of interest that humans are more susceptible to the hepatotoxic effects of nethyltestosterone than rats (Heywood etal. 1977a) or dogs (Heywood etal. 1977b). Later, an association between long-term methyltestosterone treatment and liver tumors was found (Bird et al. 1979; Boyd and Mark 1977; Coombes etal. 1978; Falk etal. 1979; Farrell etal. 1975; Goodman and Laden 1977; McCaughan et al. 1985; Paradinas et al. 1977). While these side-effects appear to be clearly related to methyltestosterone administration, the isolated observation of a seminoma in a 36-year old man on high-dose methyltestosterone seems incidental (Vogelzang etal. 1986).

The hepatotoxic side-effects are due to the alkyl group in the 17a position and have also been reported for other steroids with this configuration (Kr├╝skemper and Noell 1967). Because of the side-effects methyltestosterone should no longerbe used therapeutically for hypogonadism, in particular since effective alternatives are available (Nieschlag 1981). The German Endocrine Society declared methyltestosterone obsolete in 1981 and the German Federal Health Authority ruled that methyltestosterone should be withdrawn from the market (Methyltestosterone 1988). In other countries, however, methyltestosterone is still in use, a practice which should be terminated.

Hair Loss Prevention

Hair Loss Prevention

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